1. Field of the Invention
The present invention relates to an electronic component input device and, more particularly, to a trackball used with an electronic device, such as, for example, a telephone.
2. Prior Art
Radio telephone handsets have displays where text and graphics are displayed. A user can scroll through a menu or telephone numbers or even play games by use of arrow keys (Up/Down and/or Left/Right) on the handset. Another type of radio telephone handset interface has a roller key that rolls along a single axis. However, operating two arrow keys or a roller key and an arrow key in order to obtain a desired movement, requires the user to use more than one finger on the keys or, if only one finger is used, lift the finger between keys. This makes it harder to use the keys without actually looking at the keypad of the handset.
In accordance with one embodiment of the present invention, a trackball user input device is provided comprising a user actuated trackball; and a first trackball position sensor located at an exterior side of the trackball. The sensor comprises a first roller rotatably contacting the exterior side of the trackball. The trackball is rotatable about orthogonal axes and the exterior side of the trackball or the sensor is shaped to provide a predetermined biased stepped movement of the roller as the trackball and roller are rotated relative to each other.
In accordance with another embodiment of the present invention, a portable radio telephone is provided comprising a housing, a transceiver located in the housing, a controller connected to the transceiver, a display connected to the controller, and a user input device connected to the controller. The user input device comprises a trackball movably connected to the housing and at least one trackball rotational position sensor connected to the controller for sensing rotational movement of the trackball. The sensor includes a roller which rides against an exterior surface of the trackball. The user input device is configured to provide biased stepwise movements of the roller as the trackball is rotated by a user.
In accordance with another embodiment of the present invention an electronic device is provided having a display, a controller connected to the display, and a user input connected to the controller. The improvement comprises the user input including a trackball extending through a hole in a housing which partially encloses the trackball, rotational position tracking sensors connected to the controller and having rollers supported against an exterior surface of the trackball, and a trackball depression sensor connected to the controller for sensing depression of the trackball by a user in a direction into the housing. The trackball is both rotatable relative to the housing and depressable into the housing between a home position and a depressed position.
In accordance with one method of the present invention, a method of controlling movement of a trackball in a user interface for an electronic device is provided comprising steps of providing a biased stepwise detent positioning system for predetermined stepped rotational movement of rollers of trackball position sensors located against an exterior side of the trackball; rotating the trackball by a user; and locating the rollers at predetermined stepped positions when the user stops rotating the trackball.